Despite vast public information about smoking's negative health consequences, and the proliferation of rules limiting access to cigarettes, smoking continues to be the leading preventable cause of death and disease in the United States. Moreover, after vast declines in smoking rates following the release of the Surgeon General's seminal report, regular smoking rates have leveled at about 18% among US adults, but reaching 41% among those with General Education Diplomas. There are also race/ethnic disparities in smoking and smoking related disease. While smoking rates are highest among Caucasian and Hispanic adolescents, rates among Blacks equal Caucasians and surpass Hispanics in adults. Further, the incidence of cancers of the lungs and bronchus is 23% higher for Black than White males. Moreover, density of tobacco outlets is highest in areas in which the poor and minorities live, placing the low SES and minorities at additional risk. Yet, despite knowledge of the disproportional risks to these populations, we know little about what factors predispose low socioeconomic status (SES) and minority populations to smoke, and why and how smoking rates among minorities change with age. The proposed study will take full advantage of an existing large and extensive nationally representative longitudinal dataset, the Panel Study of Income Dynamics (PSID) and its supplements to fill these research gaps. This PSID and its child development supplement and Transition to Adulthood extensions provide unparalleled rich data to identify the factors affecting behavior across generations, and critical o our purpose, oversample low income and Black participants. As such, using this tremendous data source will allow us to comprehensively assess smoking trajectories and the contextual and person factors influencing the initiation of smoking and progression to regular smoking in low SES and minority youth and young adults. Further, and critical for public health policy, with access to PSID neighborhood data, we will identify and map the density of tobacco outlets to establish an index of exposure to smoking influences, providing the most conclusive answer to date on the relative influence of contextual and person factors on smoking behavior. As such, our aims are to identify the various smoking trajectories among low SES and minority adolescents and young adults, and the specific contextual, behavioral, and person factors characterizing the different trajectories of smoking. The results of the proposed study will provide critical data to inform a future smoking prevention study tailored to reduce health disparities related to smoking.